如果已分配，從列表中刪除產品

Question

如果已將產品分配給客戶，我如何從下拉列表中刪除產品？

該ID似乎按正確的順序。並且我做了一些改變，也許我錯過了一些東西

 public ActionResult Edit(int id = 0) 
    {  
     UserProfile userprofile = db.UserProfiles.Find(id); 

     if (userprofile == null) 
     { 
      return HttpNotFound(); 
     } 

     var deviceList = db.Devices.ToList(); 
     var userList = db.UserProfiles.ToList(); 

     foreach (var user in userList) 
     { 
      deviceList.RemoveAll(x=>x.DeviceID==user.Device_DeviceID);   

     } 

      ViewBag.deviceList = new SelectList(db.Devices, "DeviceID", "DeviceIMEI", userprofile.Device_DeviceID);    
      return View(userprofile); 

    } 

    // POST: /User/Edit/5 
    [HttpPost] 
    public ActionResult Edit(UserProfile userprofile) 
    {      
     if (ModelState.IsValid) 
     { 
      db.Entry(userprofile).State = EntityState.Modified; 

      //db.UserProfiles.Attach(userprofile); 

      db.SaveChanges(); 

      return RedirectToAction("Index"); 
     } 
     ViewBag.deviceList= new SelectList(db.Devices, "DeviceID", "DeviceIMEI", userprofile.Device_DeviceID);    
     return View(userprofile); 
    } 

Answer 1

嘗試RemoveAll方法。

var deviceList = db.Devices.ToList(); 
var userList = db.UserProfiles.ToList(); 
foreach (var user in userList) 
{ 
    deviceList.RemoveAll(x=>x.DeviceID==user.Device_DevideID); 
} 

現在，您可以將devicelist綁定到您的視圖下拉菜單。我強烈建議避免使用ViewBag/ViewData方法並切換到強類型視圖方法。